Evidence for the existence of localized plastic flow au-to-waves generated in deforming metals

Lev B Zuev,Svetlana A Barannikova

doi:10.4236/ns.2010.25059

Lev B Zuev, Svetlana A Barannikova

Open Access

https://doi.org/10.4236/ns.2010.25059

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Abstract

The localized plastic flow auto-waves observed for the stages of easy glide and linear work hardening in a number of metals are considered. The propagation rates were determined expe- rimentally for the auto-waves in question with the aid of focused-image holography. The dispersion relation of quadratic form derived for localized plastic flow auto-waves and the dependencies of phase and group rates on wave number are discussed. A detailed comparison of the quantitative characteristics of phase and group waves has revealed that the two types of wave are closely related. An invariant is introduced for localized plastic flow phenomena occurring on the micro-and macro-scale levels in the deforming solid.

Highlights

The experimental evidence obtained previously [1,2,3,4] suggests that the plastic deformation tends to localize in the deforming solid over the entire flow process
Plastic flow localization is most pronounced on the macro-scale level where the type of local strain pattern is governed by the law of work hardening acting at a given flow stage, i.e. E 1 d d
A considerable body of experimental and theoretical evidence pertaining to plastic flow macro-localization has been obtained far [1,2,3,4,6], which suggests that the macro-scale inhomogeneities of localized plastic flow have a typical scale of about 10–2 m

Summary

Introduction

The experimental evidence obtained previously [1,2,3,4] suggests that the plastic deformation tends to localize in the deforming solid over the entire flow process. A considerable body of experimental and theoretical evidence pertaining to plastic flow macro-localization has been obtained far [1,2,3,4,6], which suggests that the macro-scale inhomogeneities of localized plastic flow have a typical scale of about 10–2 m. A characteristic picture is created in the deforming specimen where deformed material zones move in a concerted manner, generating thereby localized plastic flow auto-waves, which have typical wavelength of about 10–2 m. Hacken [9], the spontaneous emergence of plastic flow inhomogeneities might be regarded as a manifestation of self-organization processes occurring in the deforming medium

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